Improvement in air-injecting nozzles



- 2 Sheets-Sheet 2. D. C. GREEN- Air-Injecting Nozzle.

No. 221,726. Patented Nov. 18,1879.

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DAVID C. GREEN, or BROOKLYN, NEW 'YonK.

IMPROVEMENT IN AIR-INJECTING NOZZLES.

Specification forming part of Letters Patent No. 221,726, dated November18, 1879; application filed September 1, 1879.

To all whom it may concern.-

Be it known that I, DAVID C. GREEN, of Brooklyn, Kings county, New York,have invented certain new and useful Improvements in Air-InjectingNozzles, of which the following is a specification.

My invention relates to apparatus for producing blasts or currents ofair, for ventilation or other purposes, by the injective action of jetsof steam or compressed air discharged from nozzles into suction throatsor tubes, through which a large volume of air is thus caused to flow bythe inducing action of the jet; and my invention is embodied mainly inan improved form of injection nozzle or jet, whereby the velocity andpressure of the jet are maintained independentof variations in thevolume supplied to it from the compressingpump or other apparatus, thusgreatly increasing the effectiveness of the jet, and causing itseffectiveness to at all times correspond proportionately with the volumesupplied, as hereinafter fully set forth.

Figure 1 of the annexed drawings is a longitudinal section of myimproved air-injector nozzle, and Fig. 2 an end View of the inner end ofthe valve-plug. Fig. 3 represents a ventilating apparatus provided withmy improved nozzles.

In producing air currents or blasts by the injective or inducing actionof jets it is necessary, as is well known, that the jet be dischargedunder a positive pressure and at a high velocity in order to obtain aneffective inducing action. The pressure, of course, mainly determinesthe velocity of the jet, and it is found that the best effect isobtained with a jet of a certain pressure and velocity, which, ofcourse, varies in different cases but when this point is determined ineach case, it cannot be much departed from without serious loss.

The volume of the jet is, of course, another element in itseffectiveness; but if its pressure p and velocity be maintaineditseffectivness will be also maintained, and will correspond with itsincrease or decrease of volume, while, if its power and velocity beallowed to fall or vary much from the best determined point, theincrease in volume will give no corresponding effectiveness, but will bemainly a loss of power. Hence the main defects in air-jet nozzles asheretofore constructed, and which I am to overcome, is that they areformed with a discharge-aperture of a fixed and uniform area, so that tomaintain the pressure and velocity of the jet up to its point ofgreatest efficiency it is necessary that the compressingpump or othersource of supply form a constant volume, corresponding to such pressureand velocity from ajet of that area, and if the volume increase ordecrease beyond-this point, the area of the jet then, of course, becomesproportionately too small or too large, hence causin g the pressure andvelocity of the jet to correspondingly decrease or increase, and thusrendering its action inefficient.

Now, the main feature of my invention may be stated to consist inconstructing the airjet nozzle with an automatic valve, arranged togovern its discharge-aperture, and loaded to open at a certain pressure,so that, hence, the jet is discharged uniformly at this pressure; andshould the supply to the jet decrease in ,volume, the valve will partlyclose to correspondingly reduce the area of the dischargeaperture, andthus maintain the uniform pressure and velocity of the jet; and shouldthe volume increase, the valve will open wider, thus discharging a jetof greater volume, yet at practically the same pressure, thusmaintaining the efficiency of the jet under a varying supply, causingthe volume of the induced current to increase proportionately as thevolume of the inducing-jet increases.

In Fig. 1, A indicates the casing or body of my improved injector valveor nozzle, and b the nozzle end thereof, in the aperture of which, asillustrated, is arranged a valveplug, B, which, when quiescent, fullycloses said aperture, preventing any discharge from the nozzle.

The outer extremity of the valve-plug is preferably of an elongatedtapering form, as illustrated its middle, or that part which fills andcloses the aperture of the nozzle, is cylindrical, to form a close fitfor the nozzle-aperture, while its inner part is also tapering, to form,as the valve is pressed out of the nozzle, an annular outlet, whichincreases in area in proportion to the distance it is pressed out, aswill be readily understood. From this inner tapering part of thevalve-plug short radial ribs 0 0 project, as shown in Figs. 1 and 2, butextend only to the same diameter as the cylindrical or plain part of thevalve, as illustrated, thus forming grooves between each other, throughwhich the air escapes, while the ribs serve to guide the plug centrallyin the nozzle aperture.

The stem d of the valve is provided either with adjustable weights or astrong spring, e, as illustrated, which constantly tends to keep theplug drawn in, and thus close the nozzleaperture, and which may beadjusted so as to place any desired pressure on the valve, so that thejet will be discharged from the nozzle at this pressure only.

Where the jetis so arranged as to discharge upwardly, weights may beused to load the stem instead of a spring; but for all other situationsI prefer to use a strong spring, as shown in Fig. l, of such length thatits tension will not vary much with a slight compression or extensionthereof.

The spring may be adjusted to place the required pressure on the valveby the adjusting and jam nuts fg, as will be readily understood, and thespring and stem may be inclosed in an air-tight tube projecting from theneck of the valve-casing, thus enabling the packing of the stem to bedispensed with, and therefore securing a more sensitive action of thevalve; but, if desired, the inclosing-tubc may be omitted, and the stempassed through a gland in the neck of the valve-casing, 1eaving thespring and stem exposed.

The nozzle is connected to the air-supply pipe, preferably, by a branchor coupling on the side of the casing A, as shown in Figs. 1 and 3, andfor ordinary ventilating purposes the air is supplied to the nozzleunder a pressure of about live pounds to the square inch.

In Fig.3 is illustrated the manner in which my improved nozzles arearranged in a ventilating apparatus. (J indicates the apartment to beventilated, which may be in a war or passenger vessel, building, mine,or elsewhere. Dis an air-compressing pump, which draws in theatmospheric air through pipe k, and discharges the compressed airthrough the pipe I, which terminates with several of the improvednozzles A. arranged in ventilating-passages leading into and out of theapartment. These nozzles are arranged to discharge into contractedsuction-throats m m, through which a large volume of atmospheric air isthus induced to tlow into and out of the apartment by the injectingaction of the jet, as will be readily understood, and these throats arepreferably made adjustable toward the nozzle, so as to obtain the bestrelative position thereof. If the valves of the injector-nozzles be nowset to the required pressure, and the air-pump D put in motion, the

nozzle-valves will confine the air till it attains the desired pressure,when the valve will open, allowing the discharge of an energetic jetfrom the nozzle, having the required velocity and pressure to produce anefl'ective iuducing action, and thus cause a strong induced current toflow through the suctionthroats with the inducing-jet. Should, however,the speed of the pump decrease, rendering the supply to the nozzle less,or should it increase, rendering the supply greater, the nozzle-valvewill partly close or open correspondingly, thus causing the volume ofthe jet to always correspond to the volume of its supply, while itspressure and velocity are maintained practically uniform, thus causingthe jet to act to its greatest efl'iciency under the differentvariations in volume, and producing, under difl'erent volumes, atcorresponding and full efliciency.

By means of these antomatically-actin g nozzles, it is found that thevolume of the inducing-jet being one, the volume of the induced currentwill be thirty-five, thus practically obtaining from one pump thecapacity of thirtyfive pumps.

The improved nozzle may, of course, be used for producing air blasts orcurrents for other purposes than ventilation, and it will also beunderstood that in some cases the nozzle may be supplied with live steaminstead of compressed air; but the use of the latter is more generallycontemplated.

I sometimes prefer to construct the valveplug of the nozzle so as todischarge a central jet as well as an annular one, the center of theplug in this case being provided with a bore arranged to embrace andslide overa tapering plug fixed in the center of the nozzle, as shown inFig. 4; but this is optional.

What I claim as my invention is- An injector-nozzle for producing blastsor currents of air, constructed with an automatic valve arranged togovern its discharge-aperture, and adjustable by spring or weights toopen and discharge the jet at a certain determined pressure, whereby thepressure and velocity of the jet are maintained practically uniformunder varying volumes, and its efficiency thus rendered constant andproportional to the volume supplied, substantially as herein set forth.

DAVID C. GREEN. Witnesses:

Guns. M. Brooms, J our: E. GAVIN.

